| Abstract: | This paper addresses the development of a new radiopharmaceutical for cancer imaging and therapy. The optimization of the labeling conditions of thymidine analogue, melphalan, with125I is described. High radiochemical yield 96.8% was obtained by reacting 0.2 mg melphalan with 125I in the presence of choloramin‐T as oxidizing agent in 0.5 M phosphate buffer, pH 7, at 70°C for 15 min. Preliminary in vivo study was done in non‐tumor bearing mice. The results revealed that this new tracer,125I‐melphalan, has a high affinity to be localized in the tumor site for a long period, which indicates the specificity of this tracer to the tumor cells. The labeled compound was cleared quickly from most of the body organs. These findings suggest that 125I‐melphalan allows imaging and treatment of cancer. 125I‐melphalan meets most of the requirements necessary to be used as a successful diagnostic and therapeutic agent: it is a low‐molecular‐weight molecule that diffuses readily in the tissues, and dose not induce an antibody response. Copyright © 2009 John Wiley & Sons, Ltd. |
